I need some help please..

My Steering Servo died, and I need a new one, but I couldn't find the right one? Part number?
I already bought the '(H)02073' [link=http://www.nitrorcx.com/51c00-02073.html]Servo[/link] Because this was the only one that stood in my manual.
When I tried to put it on my car, it didn't fit, so i concluded I had the wrong one:S dont even know if 3kg pullforce is enough? or what it has to be?
Does anyone know which servo will fit and is good enough?